Expansible collar

ABSTRACT

A double wall inflatable cylinder of elastomeric material having a pair of overlapping layers of cords extending in intersecting relationship at an angle to a line extending axially of the cylinder for compact storage in the retracted position, maximum expansion of the outer wall and gripping of a core by the inner wall in the inflated condition. A layer of circumferentially extending cords at one edge of the cylinder limits expansion of the cylinder at that edge and the walls are invaginated at the other edge to provide a double fold for compact stowage.

it] States May [151 fimdfill [45] Mar. M, 1972 [54] EXPANSTBLE CULLA[21] Appl. No.: 25,150

Mosshart et a1. ..l52/356 1,367,225 2/1921 Barker ..9/340 X 2,309,2561/1943 Rekersdres 1,998,805 4/1935 Driggs ..1 14/20 PrimaryExaminer-Milton Buchler Assistant ExaminerGregory W. OConmorAttorney-John D. Haney and Harold S. Meyer [57] AESTMRACT A double wallinflatable cylinder of elastomeric material having a pair of overlappinglayers of cords extending in intersecting relationship at an angle to aline extending axially of the cylinder for compact storage in theretracted position, max imum expansion of the outer wall and gripping ofa core by the inner wall in the inflated condition. A layer ofcircumferentially extending cords at one edge of the cylinder limitsexpansion of the cylinder at that edge and the walls are invaginated atthe other edge to provide a double fold for compact stowage.

7 Claims, 7 Drawing Figures Fuel INVENTOR.

ERALD L0 BY m 'TTW,

PATENTEBMARWWE 8,6A8.3l2

sum 2 or 3 INVENTOR. @ERMLH L NW3? "WWW ATTY.

EXPANSIBLE Cort/tn BACKGROUND OF THE INVENTION This invention relates toan expansible collar of the type which is carried by a projectile suchas a torpedo and is inflatable to provide sufficient buoyancy so thatthe projectile will float and therefore be in a position to be recoveredand used again. Collars of this type are also used as a brake to reducethe speed of the projectile through the water after it has been used sothat it may be more easily recovered.

It is possible to use practice torpedoes at less than tactical grossweight to insure they will float after their run; however, it isdesirable that these practice torpedoes be operated under normaltactical conditions and therefore expansible collars of this type areneeded.

Inflatable bags have been used to float torpedoes; however, these bagshave presented certain problems. In order to provide the volumenecessary for buoyancy, the bags were folded and had many pleats whichhad to be laid in position so that the bags would fit in the limitedspace provided and not have wrinkles at the surface which wouldinterfere with the opera tion of the torpedo. To reuse the bags, theyhad to be refolded and the proper stowage of the bags was an exactingand tedious time-consuming operation. Another problem with the foldedbags was that during expansion, one side would expand before the otherin a random manner which would turn the torpedo if it was still movingthrough the water. The moving torpedo would also exert high stresses onthe bags causing rupture of the walls. These bags also had a lowbursting strength and it was necessary to provide precise control of thegas pressure withing the bags.

The high cost of torpedoes used for practice and in development makes itimperative that they be recovered with dispatch and be ready for reusein the shortest possible time. It is evident from the above that thefolded bag type gear which has been used heretofore has not met theserequirements.

SUMMARY OF THE INVENTION The expansible collar of this inventionprovides a collar of elastomeric material which presents a smooth outersurface, fits in a small space in the surface of the torpedo, expands toa large volume to provide the necessary buoyancy to float the torpedoand automatically retracts to the original position when deflatedwithout requiring any restowing of the gear. During expansion the collarassumes a streamline shape and the expansion is concentric resulting inbraking action which does not turn the torpedo or generate excessiveforces in the walls of the collar.

Inflation of the collar requires a relatively low gas pressure; however,the construction is such that it will withstand high pressures andtherefore the pressure controls for this equipment need not be of ahighly sophisticated and expensive construction to regulate gaspressure.

Control of the expansion of the collar during inflation is providedthrough the use of layers of high strength cord fabric embedded in abody of the elastomeric material with the cords of overlapping layershaving opposite bias angles. The space required to stow the collar iskept at a minimum by making use of a construction in which the wall ofthe collar is invaginated at one edge and whereby a double fold producesfour thicknesses of the wall for stowage in the recess provided.Preferably, this invagjnated edge is at the aft end so that as thecollar expands, the forward edge will expand at a slower rate than theaft edge. A layer of cord fabric with cords extending in thecircumferential direction may be built into the forward edge of thecollar to further reduce initial expansion of that portion of thecollar.

The resilient nature of the collar permits it to be stretched over thetorpedo during installation and snapped into place in the recessprovided. The collar may have a flange at the forward end to secure thebody of the collar in the recess of the torpedo. The construction of thecollar is such that it will not roll over on itself during expansion andtherefore has the necessary stability.

The accompanying drawings show one preferred form of expansible collarmade in accordance with and embodying this invention and which isrepresentative of how this invention may be practiced.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. l is a plan view of a torpedo showing the expansible flotationcollar in the inflated condition.

FIG. 2 is an enlarged fragmentary view of the apparatus shown in FIG. 1with the expansible flotation collar shown in half section to illustratethe position of the walls in the inflated condition.

FIG. 3 is a view like FIG. 2 showing the expansible collar in thepartially inflated condition.

FIG. 4 is a view like FIG. 3 showing the expansible collar in thedeflated condition and stowed away in the recess on the torpedo surface.

FIG. 5 is an enlarged fragmentary sectional view of the forward end ofthe expansible collar shown in FIG. 4i illustrating the layers of cordfabric in detail.

FIG. 6 is a fragmentary plan view of the forward end of the expansiblecollar in the deflated condition with parts being broken away to showthe disposition of the cords in the overlapping layers of cord fabric.

FIG. 7 is a view like FIG. 5 but showing the inflation port in thecollar.

DETAILED DESCRIPTION Referring to FIG. 11, a schematic view of a torpedoI0 is shown on which a flotation collar 11 is mounted and is shown inthe full inflated condition. As shown in FIG. 2 in more detail, thecollar III is a hollow annular body or double wall cylinder seated in acircumferential recess 12 in the torpedo surface. The collar 11 has aninner wall 13 which abuts the surface of the recess, and an outer wall Mwhich expands during inflation and contracts during deflation of thecollar.

As described heretofore, FIG. 2 shows the collar III in the fullinflated condition providing the maximum buoyancy with the maximumvolume. FIG. 3 shows a view of the collar II in the partially inflatedcondition in which the outer wall M has a tapered contour presenting astreamline surface for braking of the torpedo. It will be noted thatforward edge 15 of the collar ll 1 has not expanded as much as aft edgeIn and this provides the tapered contour in this partially inflatedcondition. The completely deflated and retracted position of the collar1111 is shown in FIG. 4. The inner wall 13 and the outer wall Ml havebeen invaginated at the aft edge providing a double fold and acircumferential folded portion 17 which extends forwardly of the collar11 and reduces the length of the recess which is required for stowage ofthe collar.

Referring to FIG. 5, l5 and 7, a more detailed construction of theflotation collar III is shown. The collar Ill may be made of anelastomeric material which preferably is highly elastic and has highelongation properties. A material which will provide good adhesion tocord fabric is also desirable and in the present embodiment, naturalrubber is used. Within the body of the collar 11 of the elastomericmaterial are overlapping layers of cord fabric which are laid on thebias. The number of layers depends on the strength requirement; however,they should be in multiples of two and in the present embodiment twolayers are shown. The cords are of a high strength type and may be ofrayon, nylon or other material. Stretch cord may also be used ifdesired. In the present embodiment, nylon having a strength of 1,600pounds per square inch of width is used.

As shown in FIG. 5, an inner layer Id of cord fabric overlaps an outerlayer 119 of cord fabric and these layers extend through the inner wall113 and outer wall M of the collar ll forming an airtight chamber 22which may be inflated. At the forward edge 15 a retaining layer 23 ofcord fabric is interposed between the inner layer llfl and the outerlayer 19 of the inner wall 13 for restricting the expansion of theforward edge and holding the collar 11 in the recess 12 of the torpedo.

Referring to FIG. 6, outer wall 14 is cut away to show cords 24 of outerlayer 19 which are disposed at a relatively small bias angle to a lineextending axially of the collar which is represented by center line XXshown in the drawing. This bias angle a may be in the range of 14 to 26degrees and is approximately l8 degrees in this embodiment. The innerlayer 18 has cords 25 which extend at a small bias angle to the centerXX with the angle being represented on the drawing by b. It ispreferable that the bias angle a equals bias angle b" and that the cords24 and 25 intersect or cross. As the collar 11 expands the cords 24 and25 will pantograph and the bias angles a and b will increase to a pointwhere they are approximately 55 degrees to the center line XX whereuponthe cords will lockup and fix the outer diameter of the inflated collar.

The retaining layer 23 has cords 26 extending substantiallycircumferentially of the collar to limit the expansion of the retaininglayer during inflation and deflation of the collar 11. At the radiallyinner surface of the forward edge 15 of the collar, a folded edge orflange 27 extends under the retaining layer 23 and with the retaininglayer, helps to secure the collar 11 in the recess 12. Referring to FIG.7, a valve spud 28 having an opening 29 and secondary orifices 32through which inflating gas may be injected into the collar 11 from gasproducing means within the torpedo is shown. This valve spud 28 has aflange 33 which may be interposed between the inner layer 18 and outerlayer 19 and adhered thereto by a suitable adhesive. The valve spud 28may extend through an opening 34 in the wall of the torpedo 10 and havea threaded surface for receiving a threaded retaining ring 35.

To install the collar 11, it may be slipped over the end of the torpedol and to the recess 12 in a stretched condition. This is possible due tothe resiliency of the elastomeric material and the disposition of thecords 24 and 25 in the layer of fabric 18 and 19. The valve spud 28 isfitted in the opening 34 in the wall of the torpedo and secured by theretaining ring 35. The torpedo is then ready for operation with thecollar 11 in the position shown in FIG. 4.

When the torpedo 10 is launched as in target practice or in tests, a gasproducing device within the torpedo which is connected to the valve spud28 is actuated after a predetermined time or at a certain signal. Thegasis then injected into the chamber 22 of the collar 11 and expands theouter wall to the shape shown in FIG. 3. The operating pressure may bein the range of five p.s.i. to 30 p.s.i. The angular disposition of thecords 24 and 25 of the outer layer 19 and inner layer 18 respectivelypermits this expansion and the circumferential disposition of the cords26 of the retaining layer 23 retard the expansion of the forward edge toprovide the tapered or cone-shaped contour shown in FIG. 3. In thisposition the collar 11 provides a smooth surface which is equallyresistant to water flow along the torpedo and provides braking withoutturning the torpedo or damaging the collar itself. This braking actionalso limits the travel of the torpedo and therefore makes recoveryeasier.

Finally, in the fully inflated condition of the collar shown in FIG. 1and FIG. 2, the inner wall 13 and outer wall 14 are stretched to thelimit permitted by the cords 24 and to provide a maximum volume of thechamber 22. The disposition of the cords at the angles a" and b shown inFIG. 6 also provide for gripping of the surface of the torpedo at recess12 by the inner wall 13 during expansion so that the collar 11 will havethe necessary stability and stay in place.

After the torpedo has been recovered, the gas is released from thecollar 11 and because of the construction of the collar as describedheretofore, it will retract to the position shown in FIG. 4 and be readyfor another use. Removal of the collar is also accomplished with easesimply by disconnecting the valve spud 28 and pulling the collar overthe torpedo and off the end.

What is claimed is:

1. An inflatable expansible collar occupying a small space in a deflatedretracted condition and expanding to contain a substantially largevolume of gas in the inflated condition comtubular annular body ofelastomenc material having prising a an inner wall, and outer wall andoverlapping layers of cords adhered to said material and extendingthrough said inner wall and said outer wall, an inner layer, an outerlayer and a means for inflating and deflating said body, said innerlayer having cords disposed at an angle to a line extending axially ofsaid collar, said outer layer having cords extending at an angle to saidline on the opposite side of said line for controlled expansion andcomplete return to the deflated condition of said body, a retaininglayer of substantially circumferentially extending cords embedded in andadhered to said elastomeric material of said inner wall providing forlimited stretching of said retaining layer and resilient gripping of asupporting body within said collar and said retaining layer beingdisposed at one edge of said inner wall to deter the inflation of thatedge and the adjoining edge of said outer wall during expansion toprovide a tapered contour of said body when partially inflated.

2. An inflatable expansible collar according to claim 1 wherein anopening is provided in said inner wall at a position adjacent saidretaining layer and connected to said means for inflating and deflatingsaid body.

3. An inflatable expansible collar according to claim 1 wherein a flangeextends outwardly from said inner wall outwardly from said inner walland under said retaining layer for securing the collar to anotherobject.

4. An inflatable expansible collar according to claim 1 wherein saidbody has a circumferential folded portion opening in a double fold at asecond edge of said collar spaced from said one edge of said collarproviding for maximum expansion of said body, a small stowage volume inthe retracted condition and a tapered contour of said body whenpartially inflated.

5. A torpedo brake and flotation collar comprising an annular, tubular,inflatable, expansible double wall cylinder for disposition in acircumferential recess in the outer surface of a torpedo, an inner walland an outer wall having a diameter substantially the same as the outersurface of the torpedo, said inner wall and said outer wall of saidcylinder having at least two overlapping layers of reinforcing cordembedded in and adhered to a highly elastic material, said overlappinglayers having cords extending on the bias at opposite but equal anglesto a line extending axially of said cylinder, gas producing means withinthe torpedo connected to said cylinder through an opening in said innerwall of said cylinder for inflating and expanding the cylinder to brakemovement through the water during partial expansion and provide thenecessary buoyancy to float the torpedo when fully expanded, a retaininglayer of substantially circumferentially extending cords embedded in anadhered to said elastomeric material at the forward edge of said innerwall to provide a tapered contour of said outer wall of said cylinderduring expansion and braking of the torpedo with a streamline surface.

6. A torpedo brake and flotation collar according to claim 5 whereinsaid cylinder has a flange extending outwardly from the forward edge ofsaid inner wall and under said retaining layer for securing said collarto the walls of said recess of said torpedo.

7. A torpedo brake and flotation collar according to claim 6 whereinsaid inner wall and said outer wall of said cylinder are invaginated atthe aft edge to provide for stowing said cylinder in a recess in thetorpedo of less width than the length of the inner and outer walls ofsaid cylinder and provide for expansion of the aft edge at a faster ratethan the forward edge of the collar.

TED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 15485312Dated March 1i, 1972 Inventor(s) GERALQ L. MAY

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

' Column 3, line 3 "layer"v should read .1

--layers---.

Column 4, lines 28 and 29, (claim 3), cancel "outwardly from said innerwall".

Column 1, line 5 4, (claim 5), "an" should read -and---.

Signed and sealed this 15th day of August 1972.

(SEAL) Attest:

EDWARD M.,FLETCHER,JR. ROBERT GOTTSGHALK Attesting Officer Commissionerof Patents

1. An inflatable expansible collar occupying a small space in a deflatedretracted condition and expanding to contain a substantially largevolume of gas in the inflated condition comprising a tubular annularbody of elastomeric material having an inner wall, an outer wall andoverlapping layers of cords adhered to said material and extendingthrough said inner wall and said outer wall, an inner layer, an outerlayer and a means for inflating and deflating said body, said innerlayer having cords disposed at an angle to a line extending axially ofsaid collar, said outer layer having cords extending at an angle to saidline on the opposite side of said line for controlled expansion andcomplete return to the deflated condition of said body, a retaininglayer of substantially circumferentially extending cords embedded in andadhered to said elastomeric material of said inner wall providing forlimited stretching of said retaining layer and resilient gripping of asupporting body within said collar and said retaining layer beingdisposed at one edge of said inner wall to deter the inflation of thatedge and the adjoining edge of said outer wall during expansion toprovide a tapered contour of said body when partially inflated.
 2. Aninflatable expansible collar according to claim 1 wherein an opening isprovided in said inner wall at a position adjacent said retaining layerand connected to said means for inflating and deflating said body.
 3. Aninflatable expansible collar according to claim 1 wherein a flangeextends outwardly from said inner wall outwardly from said inner walland under said retaining layer for securing the collar to anotherobject.
 4. An inflatable expansible collar according to claim 1 whereinsaid body has a circumferential folded portion opening in a double foldat a second edge of said collar spaced from said one edge of said collarproviding for maximum expansion of said body, a small stowage volume inthe retracted condition and a tapered contour of said body whenpartially inflated.
 5. A torpedo brake and flotation collar comprisingan annular, tubular, inflatable, expansible double wall cylinder fordisposition in a circumferential recess in the outer surface of atorpedo, an inner wall and an outer wall having a diameter substantiallythe same as the outer surface of the torpedo, said inner wall and saidouter wall of said cylinder having At least two overlapping layers ofreinforcing cord embedded in and adhered to a highly elastic material,said overlapping layers having cords extending on the bias at oppositebut equal angles to a line extending axially of said cylinder, gasproducing means within the torpedo connected to said cylinder through anopening in said inner wall of said cylinder for inflating and expandingthe cylinder to brake movement through the water during partialexpansion and provide the necessary buoyancy to float the torpedo whenfully expanded, a retaining layer of substantially circumferentiallyextending cords embedded in an adhered to said elastomeric material atthe forward edge of said inner wall to provide a tapered contour of saidouter wall of said cylinder during expansion and braking of the torpedowith a streamline surface.
 6. A torpedo brake and flotation collaraccording to claim 5 wherein said cylinder has a flange extendingoutwardly from the forward edge of said inner wall and under saidretaining layer for securing said collar to the walls of said recess ofsaid torpedo.
 7. A torpedo brake and flotation collar according to claim6 wherein said inner wall and said outer wall of said cylinder areinvaginated at the aft edge to provide for stowing said cylinder in arecess in the torpedo of less width than the length of the inner andouter walls of said cylinder and provide for expansion of the aft edgeat a faster rate than the forward edge of the collar.